The disclosures herein relate in general to electronic circuitry, and in particular to a method and circuitry for regulating a voltage.
A regulator can output a regulated supply voltage to a processor (e.g., one or more microprocessors, microcontrollers and/or digital signal processors). In one example, the regulator is specified to output the regulated supply voltage at 1.2 volts (“target voltage”). However, if an undershoot condition occurs (e.g., in which the regulated supply voltage is at least 36 millivolts below the target voltage), then the processor may automatically reset.
By comparison, the processor may tolerate an overshoot condition (e.g., in which the regulated supply voltage is more than a predetermined level above the target voltage), so long as the overshoot condition has a relatively short duration (e.g., measured in milliseconds). Nevertheless, if the processor has a step down (e.g., 500 mA in 1 μs) of load current, then it may cause the overshoot condition followed by the undershoot condition. To reduce the overshoot condition, one conventional technique uses a state machine to control a pull down (of the regulated supply voltage) for a predetermined constant duration, but the predetermined constant duration may be unsuitable if variation occurs in one or more environmental (e.g., process, voltage and/or temperature) conditions.